The present invention relates to a device for correcting teeth irregularities (malalignment), and more particularly, to a correcting device which can correct malalignment with no need of tying a wire to brackets.
A conventional correcting device has, for example, as shown in FIG. 21, brackets 52, a wire 53 and strings 54 for tying the brackets to the wire. Each bracket is provided with a slit (wire-engaging-slit) 51 for catching the wire 53. The wire 53 is inserted through a series of the slits of the brackets 52, and is supported thereby.
The wire 53 has a generally round shape in cross section, and sometimes a square shape.
In use of the device, each bracket 52 is fixed on each tooth T of the malalignment. The wire 53 is inserted through the series of slits 51 of brackets 52, and then, the wire 53 is bent in such way that spring force of the wire 53 is applied upon the teeth to correct the alignment, and the wire is tied on the brackets by means of the strings 54 with utilizing grooves 55 in the side surfaces of the brackets 52.
In the conventional device, it is very complicated to fasten the wire 53 to each bracket 52 and high skill is required, and moreover it takes much time to perform the fastening work. Especially, during the correction of malalignment, which may take a few months, the wire has to be changed to a new wire having higher elastic force several times, since the elastic force becomes weakened by gradual moving of the teeth.
Consequently, both the orthodontist and the patient complicated and laborious procedure whenever the wire is changed.
Further, in case a correcting torque is applied against the bracket by utilizing a square sectional wire in order to correct an inclination or twist of teeth, it is difficult to fasten the wire to the bracket, and highly refined technique is required for fixing the wire such that torque is sufficiently transmitted.
In addition, since the conventional wire is made of a metal, the wire is bright and conspicuous, and the appearance is bad in use. Further, users may have an adverse feeling about the wire.
In the conventional device, special brackets having cylindrical shape are used in order to fix both ends of the wire, and consequently, the patient feels disconfort in the mouth.
A main object of the present invention is to delete the above-mentioned problems and to provide a device for correcting teeth irregularities, which is easily attached to the teeth facilitates changing a wire, and creates a less adverse feeling in use.
Another object of the present invention is to provide a device for correcting teeth irregularities by using a plastic wire which has high resistance to creep and has large geometrical moment of inertia of its cross sectional area.
In the conventional correcting method, it is difficult to fix the bracket to the tooth, wherein a twisted angle, inclined degree and the like are large and each shape is different, in the appropriate location and a angle.
Many kind of the bracket having different shapes of the surface to be contacted with the tooth have been conventionally prepared or processed in accordance with the shape of the tooth.
The object of the present invention is to provide a device for correcting teeth irregularities wherein the device corresponds to a tooth one-to-one and can be easily installed by providing the bracket with the base plate which can be easily processed so as to have a shape corresponding to each tooth.
As the tooth to be corrected, there are such case where the tooth is twisted, inclined, oblique, or a clearance between teeth is large. When the clearance between teeth is large, a sliding operation is required. When the twisted tooth is corrected, it sometimes happens that the sliding operation is required in the correcting step.
When one tooth is corrected by the sliding operation, the brackets which are fixed to the other teeth are corded up by a resilient material such as a rubber band to create the force of the sliding operation.
However, since the bracket is small (width is in the range from 1 to 5 mm, length is in the range of 1 to 5 mm), the rubber band is difficult to engage and sometimes slips off.
The present invention provides a supplementary device wherein an installation and removal can be easily performed.